Elements Can Be Classified by Their Position in the Periodic Table

Elements Can Be Classified by Their Position in the Periodic Table 

The lanthanides and actinides are sometimes called /-block transition elements because they have incompletely filled / subshells. Figme 2.14 distinguishes these groups of elements discussed here. 

Chapter 2 Many-Electron Atoms and the Periodic Tabie 

An atom of a certain element has 15 electrons. Without consulting a periodic table, answer the following questions (a) What is the ground-state electron configuration of the element (b) How should the element be classified (c) Is the element diamagnetic or paramagnetic  

Strategy (a) Use the building-up principle discussed in Section 2.2 to write the electron configuration with principal quantum number n = 1 and continue upward until all the electrons are accounted for. (b) To determine whether the atom should be classified as a representative element, a transition metal, or a noble gas, consider its electron configuration characteristics, (c) Examine the pairing scheme of the electrons in the outermost shell. The element will be diamagnetic if all electrons are paired and paramagnetic if some are unpaired. 

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